%0 Journal Article
%T Exploration of Charge Recycling DC-DC Conversion Using a Switched Capacitor Regulator
%A Kaushik Mazumdar
%A Mircea R. Stan
%J Journal of Low Power Electronics and Applications
%D 2013
%I MDPI AG
%R 10.3390/jlpea3030250
%X The increasing popularity of DVFS (dynamic voltage frequency scaling) schemes for portable low power applications demands highly efficient on-chip DC-DC converters. The primary aim of this work is to enable increased efficiency of on-chip DC-DC conversion for near-threshold operation of multicore chips. The idea is to supply nominal (high) off-chip voltage to the cores which are then ¡°voltage-stacked¡± to generate the near-threshold (low) voltages based on Kirchhoff¡¯s voltage law through charge recycling. However, the effectiveness of this implicit down-conversion is affected by the current imbalance among the cores. The paper presents a design methodology and optimization strategy for highly efficient charge recycling on-chip regulation using a push-pull switched capacitor (SC) circuit. A dual-boundary hysteretic feedback control circuit has been designed for stacked loads. A stacked-voltage domain with its self-regulation capability combined with a SC converter has shown average efficiency of 78%¨C93% for 2:1 down-conversion with I Load (max) of 200 mA and workload imbalance varying from 0¨C100%.
%K voltage stacking
%K charge recycling
%K DC-DC converter
%K switched capacitor
%K energy efficiency
%K near-threshold
%K hysteresis feedback
%K ripple
%K phase interleaving
%U http://www.mdpi.com/2079-9268/3/3/250